Selectivity test

Abstract

Testing radio equipment is described wherein an interfering signal is swept in frequency with a step size that is chosen proportional to the bandwidth of the receive channel of the radio equipment. For example, a respective frequency bandwidth (B Ch ) is determined of a plurality of receive channels of the radio equipment. A proportionality constant is selected for a frequency step size. For each respective receive channel, interfering radio signals are generated and the interfering radio signals are controlled to stepwise sweep in frequency outside of each respective receive channel. The stepwise sweeping of the interfering frequency is performed with a frequency step size that is a product of the respective bandwidth and the selected proportionality constant. Any spurious response is detected in the respective receive channel.

The invention claimed is: 
     
       1. A method for testing radio equipment comprising:
 generating an interfering signal; 
 determining a respective frequency bandwidth (B Ch ) of a plurality of receive channels of the radio equipment; 
 selecting a proportionality constant for a frequency step size for each respective receive channel; 
 generating, for each respective receive channel, interfering radio signals and controlling the interfering radio signals to stepwise sweep in frequency outside of each respective receive channel, where the stepwise sweeping of the interfering frequency is performed with the respective frequency step size that is a product of the respective bandwidth and the selected proportionality constant; and 
 detecting any spurious response in the respective receive channel. 
 
     
     
       2. The method of  claim 1  wherein the selection of the proportionality constant for a frequency step size comprises selecting a value that is less than or equal to ½. 
     
     
       3. The method of  claim 1 , wherein the selection of the proportionality constant for a frequency step size comprises selecting a value that is in an interval defined by the expression: max{S 0 ,min(└0.5B Ch ┘,S 1 )}, where S 0  is 1 MHz and S 1  is 5 MHz and the function └ . . . ┘ is the floor function, and B CH  ranges from 1.4 to 20 MHz. 
     
     
       4. An apparatus for testing radio equipment, the apparatus comprising:
 radio frequency (RF) circuitry; 
 control circuitry; and 
 memory circuitry, 
 wherein the RF circuitry, control circuity, and memory circuitry are configured to generate an interfering signal, and 
 wherein the RF circuitry, control circuitry and the memory circuitry are configured to: 
 determine a respective frequency bandwidth (B Ch ) of a plurality of receive channels of the radio equipment; 
 select a proportionality constant for a frequency step size for each respective receive channel; 
 generate, for each respective receive channel, interfering radio signals and control the interfering radio signals to stepwise sweep in frequency outside of each respective receive channel, where the stepwise sweeping of the interfering frequency is performed with the respective frequency step size that is a product of the respective bandwidth and the selected proportionality constant; and 
 detect any spurious response in the respective receive channel. 
 
     
     
       5. The apparatus of  claim 4 , wherein the configuration of the RF circuitry, control circuitry and the memory circuitry to select the proportionality constant for a frequency step size comprises a configuration to select a value that is less than or equal to ½. 
     
     
       6. The apparatus of  claim 4 , wherein the configuration of the RF circuitry, control circuitry and the memory circuitry to select the proportionality constant for a frequency step size comprises a configuration to select a value that is in an interval defined by the expression: max{S 0 ,min(└0.5B Ch ┘,S 1 )}, where S 0  is 1 MHz and S 1  is 5 MHz and the function └ . . . ┘ is the floor function, and B CH  ranges from 1.4 to 20 MHz. 
     
     
       7. A non-transitory processor readable storage medium comprising software instructions that, when executed in a processor, perform a method for testing radio equipment, the method comprising:
 generating an interfering signal; 
 determining a respective frequency bandwidth (B Ch ) of a plurality of receive channels of the radio equipment; 
 selecting a proportionality constant for a frequency step size for each respective receive channel; 
 generating, for each respective receive channel, interfering radio signals and controlling the interfering radio signals to stepwise sweep in frequency outside of each respective receive channel, where the stepwise sweeping of the interfering frequency is performed with the respective frequency step size that is a product of the respective bandwidth and the selected proportionality constant; and 
 detecting any spurious response in the respective receive channel.